eliminate use vars
[imager.git] / lib / Imager / Preprocess.pm
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9b1ec2b8 1package Imager::Preprocess;
ee64a81f 2use 5.006;
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3use strict;
4require Exporter;
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5use Getopt::Long;
6use Text::ParseWords;
9b1ec2b8 7
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8our @EXPORT = qw(preprocess);
9our @ISA = qw(Exporter);
9b1ec2b8 10
ee64a81f 11our $VERSION = "1.002";
5715f7c3 12
9b1ec2b8 13sub preprocess {
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14 unshift @ARGV, grep /^-/, shellwords($ENV{IMAGER_PREPROCESS_OPTS})
15 if $ENV{IMAGER_PREPROCESS_OPTS};
16 my $skip_lines = 0;
17 GetOptions("l" => \$skip_lines)
18 or usage();
19 my $keep_lines = !$skip_lines;
20
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21 my $src = shift @ARGV;
22 my $dest = shift @ARGV
23 or usage();
24
25 open SRC, "< $src"
26 or die "Cannot open $src: $!\n";
27
28 my $cond;
29 my $cond_line;
30 my $save_code;
31 my @code;
32 my $code_line;
33 my @out;
34 my $failed;
35
36 push @out,
37 "#define IM_ROUND_8(x) ((int)((x)+0.5))\n",
38 "#define IM_ROUND_double(x) (x)\n",
39 "#define IM_LIMIT_8(x) ((x) < 0 ? 0 : (x) > 255 ? 255 : (x))\n",
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40 "#define IM_LIMIT_double(x) ((x) < 0.0 ? 0.0 : (x) > 1.0 ? 1.0 : (x))\n";
41 push @out, "#line 1 \"$src\"\n" if $keep_lines;
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42 while (defined(my $line = <SRC>)) {
43 if ($line =~ /^\#code\s+(\S.+)$/) {
44 $save_code
45 and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
46
47 $cond = $1;
48 $cond_line = $.;
49 $code_line = $. + 1;
50 $save_code = 1;
51 }
52 elsif ($line =~ /^\#code\s*$/) {
53 $save_code
54 and do { warn "$src:$code_line:Unclosed #code block\n"; ++$failed; };
55
56 $cond = '';
57 $cond_line = 0;
58 $code_line = $. + 1;
59 $save_code = 1;
60 }
9e713610 61 elsif ($line =~ /^\#\/code\s*$/) {
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62 $save_code
63 or do { warn "$src:$.:#/code without #code\n"; ++$failed; next; };
64
65 if ($cond) {
93bc63ea 66 push @out, "#line $cond_line \"$src\"\n" if $keep_lines;
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67 push @out, " if ($cond) {\n";
68 }
69 push @out,
70 "#undef IM_EIGHT_BIT\n",
71 "#define IM_EIGHT_BIT 1\n",
72 "#undef IM_FILL_COMBINE\n",
73 "#define IM_FILL_COMBINE(fill) ((fill)->combine)\n",
74 "#undef IM_FILL_FILLER\n",
75 "#define IM_FILL_FILLER(fill) ((fill)->f_fill_with_color)\n";
93bc63ea 76 push @out, "#line $code_line \"$src\"\n" if $keep_lines;
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77 push @out, byte_samples(@code);
78 push @out, " }\n", " else {\n"
79 if $cond;
80 push @out,
81 "#undef IM_EIGHT_BIT\n",
82 "#undef IM_FILL_COMBINE\n",
83 "#define IM_FILL_COMBINE(fill) ((fill)->combinef)\n",
84 "#undef IM_FILL_FILLER\n",
85 "#define IM_FILL_FILLER(fill) ((fill)->f_fill_with_fcolor)\n";
93bc63ea 86 push @out, "#line $code_line \"$src\"\n" if $keep_lines;
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87 push @out, double_samples(@code);
88 push @out, " }\n"
89 if $cond;
93bc63ea 90 push @out, "#line ",$.+1," \"$src\"\n" if $keep_lines;
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91 @code = ();
92 $save_code = 0;
93 }
94 elsif ($save_code) {
95 push @code, $line;
96 }
97 else {
98 push @out, $line;
99 }
100 }
101
102 if ($save_code) {
103 warn "$src:$code_line:#code block not closed by EOF\n";
104 ++$failed;
105 }
106
107 close SRC;
108
109 $failed
110 and die "Errors during parsing, aborting\n";
111
112 open DEST, "> $dest"
113 or die "Cannot open $dest: $!\n";
114 print DEST @out;
115 close DEST;
116}
117
118sub byte_samples {
119 # important we make a copy
120 my @lines = @_;
121
122 for (@lines) {
123 s/\bIM_GPIX\b/i_gpix/g;
124 s/\bIM_GLIN\b/i_glin/g;
125 s/\bIM_PPIX\b/i_ppix/g;
126 s/\bIM_PLIN\b/i_plin/g;
127 s/\bIM_GSAMP\b/i_gsamp/g;
3c030abe 128 s/\bIM_PSAMP\b/i_psamp/g;
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129 s/\bIM_SAMPLE_MAX\b/255/g;
130 s/\bIM_SAMPLE_MAX2\b/65025/g;
131 s/\bIM_SAMPLE_T/i_sample_t/g;
132 s/\bIM_COLOR\b/i_color/g;
133 s/\bIM_WORK_T\b/int/g;
134 s/\bIM_Sf\b/"%d"/g;
135 s/\bIM_Wf\b/"%d"/g;
136 s/\bIM_SUFFIX\((\w+)\)/$1_8/g;
137 s/\bIM_ROUND\(/IM_ROUND_8(/g;
138 s/\bIM_ADAPT_COLORS\(/i_adapt_colors(/g;
139 s/\bIM_LIMIT\(/IM_LIMIT_8(/g;
140 s/\bIM_RENDER_LINE\(/i_render_line(/g;
141 s/\bIM_FILL_COMBINE_F\b/i_fill_combine_f/g;
142 }
143
144 @lines;
145}
146
147sub double_samples {
148 # important we make a copy
149 my @lines = @_;
150
151 for (@lines) {
152 s/\bIM_GPIX\b/i_gpixf/g;
153 s/\bIM_GLIN\b/i_glinf/g;
154 s/\bIM_PPIX\b/i_ppixf/g;
155 s/\bIM_PLIN\b/i_plinf/g;
156 s/\bIM_GSAMP\b/i_gsampf/g;
3c030abe 157 s/\bIM_PSAMP\b/i_psampf/g;
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158 s/\bIM_SAMPLE_MAX\b/1.0/g;
159 s/\bIM_SAMPLE_MAX2\b/1.0/g;
160 s/\bIM_SAMPLE_T/i_fsample_t/g;
161 s/\bIM_COLOR\b/i_fcolor/g;
162 s/\bIM_WORK_T\b/double/g;
163 s/\bIM_Sf\b/"%f"/g;
164 s/\bIM_Wf\b/"%f"/g;
165 s/\bIM_SUFFIX\((\w+)\)/$1_double/g;
166 s/\bIM_ROUND\(/IM_ROUND_double(/g;
167 s/\bIM_ADAPT_COLORS\(/i_adapt_fcolors(/g;
168 s/\bIM_LIMIT\(/IM_LIMIT_double(/g;
169 s/\bIM_RENDER_LINE\(/i_render_linef(/g;
170 s/\bIM_FILL_COMBINE_F\b/i_fill_combinef_f/g;
171 }
172
173 @lines;
174}
175
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176sub usage {
177 die <<EOS;
178Usage: perl -MImager::Preprocess -epreprocess [-l] infile outfile
179 -l don't produce #line directives
180 infile - input file
181 outfile output file
182
183See perldoc Imager::Preprocess for details.
184EOS
185}
186
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1871;
188
189__END__
190
191=head1 NAME
192
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193=for stopwords preprocessor
194
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195Imager::Preprocess - simple preprocessor for handling multiple sample sizes
196
197=head1 SYNOPSIS
198
199 /* in the source: */
200 #code condition true to work with 8-bit samples
201 ... code using preprocessor types/values ...
202 #/code
203
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204 # process and make #line directives
205 perl -MImager::Preprocess -epreprocess foo.im foo.c
206
207 # process and no #line directives
208 perl -MImager::Preprocess -epreprocess -l foo.im foo.c
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209
210=head1 DESCRIPTION
211
212This is a simple preprocessor that aims to reduce duplication of
213source code when implementing an algorithm both for 8-bit samples and
214double samples in Imager.
215
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216Imager's C<Makefile.PL> currently scans the F<MANIFEST> for F<.im>
217files and adds Makefile files to convert these to F<.c> files.
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218
219The beginning of a sample-independent section of code is preceded by:
220
221 #code expression
222
223where I<expression> should return true if processing should be done at
2248-bits/sample.
225
226You can also use a #code block around a function definition to produce
2278-bit and double sample versions of a function. In this case #code
228has no expression and you will need to use IM_SUFFIX() to produce
229different function names.
230
231The end of a sample-independent section of code is terminated by:
232
233 #/code
234
235#code sections cannot be nested.
236
237#/code without a starting #code is an error.
238
239The following types and values are defined in a #code section:
240
241=over
242
243=item *
244
5715f7c3 245IM_GPIX(C<im>, C<x>, C<y>, C<&col>)
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246
247=item *
248
5715f7c3 249IM_GLIN(C<im>, C<l>, C<r>, C<y>, C<colors>)
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250
251=item *
252
5715f7c3 253IM_PPIX(C<im>, C<x>, C<y>, C<&col>)
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254
255=item *
256
5715f7c3 257IM_PLIN(C<im>, C<x>, C<y>, C<colors>)
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258
259=item *
260
5715f7c3 261IM_GSAMP(C<im>, C<l>, C<r>, C<y>, C<samples>, C<chans>, C<chan_count>)
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262
263These correspond to the appropriate image function, eg. IM_GPIX()
264becomes i_gpix() or i_gpixf() as appropriate.
265
266=item *
267
5715f7c3 268IM_ADAPT_COLORS(C<dest_channels>, C<src_channels>, C<colors>, C<count>)
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269
270Call i_adapt_colors() or i_adapt_fcolors().
271
272=item *
273
5715f7c3 274IM_FILL_COMBINE(C<fill>) - retrieve the combine function from a fill
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275object.
276
277=item *
278
5715f7c3 279IM_FILL_FILLER(C<fill>) - retrieve the fill_with_* function from a fill
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280object.
281
282=item *
283
284IM_SAMPLE_MAX - maximum value for a sample
285
286=item *
287
288IM_SAMPLE_MAX2 - maximum value for a sample, squared
289
290=item *
291
292IM_SAMPLE_T - type of a sample (i_sample_t or i_fsample_t)
293
294=item *
295
296IM_COLOR - color type, either i_color or i_fcolor.
297
298=item *
299
300IM_WORK_T - working sample type, either int or double.
301
302=item *
303
304IM_Sf - format string for the sample type, C<"%d"> or C<"%f">.
305
306=item *
307
308IM_Wf - format string for the work type, C<"%d"> or C<"%f">.
309
310=item *
311
312IM_SUFFIX(identifier) - adds _8 or _double onto the end of identifier.
313
314=item *
315
316IM_EIGHT_BIT - this is a macro defined only in 8-bit/sample code.
317
318=back
319
320Other types, functions and values may be added in the future.
321
322=head1 AUTHOR
323
5b480b14 324Tony Cook <tonyc@cpan.org>
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325
326=cut